I drive with mine on, always. The ECO setting in its "on" position will control the A/C to permit a balance between economy and usability. Letting the climate control do all the decision making.
The A/C is not just for hot weather. Cold and damp conditions also require the A/C to be on. This will help clear the windscreen and quarter-lights.
The AC is on by default ....and I can't fault it...it's perfect in any conditions...and I'm won over to it...yet NEVER had it in my own previous cars!
Again, I point out that even if it takes a 'little' on the fuel economy , I'm not bothered...as IT'S GREAT!